Molecular species determination of cyathostomins from horses in Ireland

Cyathostomins are globally important equine parasites, responsible for both chronic and acute pathogenic effects. The occurrence of mixed infections with numerous cyathostomin species hinders our understanding of parasite epidemiology, host-parasite dynamics, and species pathogenicity. There have been few studies of cyathostomin species occurring in horses in Ireland, where temperate climatic conditions with year-round rainfall provide suitable conditions for infection of grazing animals with bursate nematodes. Here, we amplified and sequenced the ITS-2 region of adult worms harvested at post-mortem from eleven adult horses between August 2018 and June 2020, and recorded species prevalence and abundance of worms recovered from the caecum, right ventral colon and left dorsal colon, using both BLAST and IDTAXA for taxonomic attribution. Phylogenetic relationships and community composition were also recorded and compared with other relevant studies, including a global meta-analysis. Overall, our results agree with previous studies that there does not seem to be a major difference in cyathostomin species occurrence in equids in different geographical regions. We confirmed the results of other workers in relation to the difficulties in discriminating between Cylicostephanus calicatus and Coronocyclus coronatus on the basis of ITS-2 sequences.

Adapting the Client Priority Rating Scale to better fit the sexual health counselling setting: a quality improvement study

BACKGROUND

When demand for counselling in community-based clinics exceeds capacity, waiting lists are typically formed. Determining allocation priority solely on wait time can overlook client risk factors that can elevate priority. We undertook to rigorously adapt the only existing validated counselling triage tool, to better fit the sexual health setting.

METHODS

Sexual health counsellors were surveyed about aspects of client presentations that flagged increased priority. The revised Client Priority Rating Scale (CPRS-R) was created through systematic analysis and decision making, informed by survey results and literature review. Four expert sexual health counsellors independently rated the priority of 14 hypothetical clinical vignettes using the CPRS and CPRS-R.

RESULTS

Criterion (concurrent), content and face validity are evidenced in the revised scale. Average interrater agreement was higher on the CPRS-R (28%) than the CPRS (11%); however, this difference was marginal (P =0.06). According to Gwet's Agreement Coefficient (AC) and Krippendorff's Alpha, both the CPRS and the CPRS-R demonstrate comparable interrater reliability, substantial and moderate, respectively. Kendall's W indicates the CPRS yielded higher reliability. However, the difference is not substantial.

CONCLUSIONS

The CPRS-R is a triage tool designed for the sexual health counselling setting. This tool has demonstrated criterion, content and face validity, as well as moderate to substantial inter-rater reliability. It can be used in sexual health settings to inform assessments about client priority, along with clinical judgement and peer consultation.

The impact of developmental language disorder in a defendant's description on mock jurors' perceptions and judgements

BACKGROUND

While it has been posited that young people with language needs may be viewed more negatively (e.g., as more rude, less cooperative) than those without language needs, the impact of knowing about a person's language needs on others' perceptions has yet to experimentally tested.

AIMS

To examine whether the presence of a developmental language disorder (DLD) diagnosis in a defendant's information would affect mock juror ratings of guilt, sentence length, credibility and blameworthiness.

METHODS & PROCEDURES

A total of 143 jury eligible participants read a vignette of a non-violent crime. Half of the participants (N = 73) were told the defendant has a diagnosis of DLD, while half (N = 70) were not told.

OUTCOMES & RESULTS

Preregistered analyses found that DLD information affected ratings of credibility and blameworthiness, though not judgements of guilt or sentence length. Unregistered content analyses were applied to the justifications participants gave for their ratings: these suggested that participants who did not have the DLD information judged the defendant more on his personality and attitude, and drew more links to his (perceived) background, while participants who received the DLD information condition made more reference to him having cognitive problems.

CONCLUSIONS & IMPLICATIONS

Unlike in previous studies of the impact of autism information, information about a defendant's DLD did not affect mock jurors' likelihood of finding them guilty, or lead participants to give longer sentences. However, our findings suggest knowing a person has DLD does affect others' perceptions of credibility and blameworthiness.

WHAT THIS PAPER ADDS

What is already known on the subject There is already evidence that some conditions that affect communication, specifically autism, also affect juror perceptions. Research also shows that knowing whether or not a defendant has autism influences how jurors rate defendants. However, autism is not the only condition that is relevant to juror perceptions, as we also know that a high rate of young offenders have language needs, and many have language profiles like DLD. What this paper adds to existing knowledge There is little research on how behaviours associated with DLD impact others' perceptions. This study reports the impact of knowing about a defendant's DLD on juror perceptions, investigating whether knowing about DLD improves judgements on guilt, sentencing lengths, credibility and culpability. Beyond the content of youth offending, this study suggests behaviours associated with DLD lead people to form more negative judgements about youth with DLD. This is important because there is still a lack of awareness of DLD both in- and outside the criminal justice system. What are the potential or actual clinical implications of this work? This study shows that knowing about a person's DLD has largely positive effects on others' perceptions of them. This implies that recognizing undetected language needs in young offenders, and supporting colleagues and members of the public to know what DLD is and how it affects people, is critical for youth with DLD to be judged fairly. This study will support the case for raising awareness of vulnerability within the youth justice population, and will assist in clinicians evidencing the need for our roles in justice settings.

Attrition in longitudinal studies among patients with schizophrenia and other psychoses; findings from the STRATA collaboration

A major problem with longitudinal studies is the bias generated due to attrition, particularly apparent amongst patients suffering from psychotic disorders. Factors associated with study-participation were investigated as part of a larger research collaboration (STRATA). Out of 479 eligible participants, only 50 (10,4%) were successfully followed up. The present study investigated whether study participation differed depending on baseline characteristics. Results indicated that individuals who did not participate were more likely to report an alcohol use disorder while those who did respond were more likely to have been in full-time education for longer and be of white ethnicity. Participation did not differ depending on diagnosis, symptoms, GAF, age of onset or depression.

Genomic Profiling and Functional Analysis of let-7c miRNA-mRNA Interactions Identify SOX13 to Be Involved in Invasion and Progression of Pancreatic Cancer

BACKGROUND

Pancreatic cancer is a devastating disease; its lethality is related to rapid growth and tendency to invade adjacent organs and metastasize at an early stage.

OBJECTIVE

The aim of this study was to identify miRNAs and their gene targets involved in the invasive phenotype in pancreatic cancer to better understand the biological behaviour and the rapid progression of this disease.

METHODS

miRNA profiling was performed in isogenic matched high invasive and low-invasive subclones derived from the MiaPaCa-2 cell line and validated in a panel of pancreatic cancer cell lines, tumour, and normal pancreas. Online miRNA target prediction algorithms and gene expression arrays were used to predict the target genes of the differentially expressed miRNAs. miRNAs and potential target genes were subjected to overexpression and knockdown approaches and downstream functional assays to determine their pathological role in pancreatic cancer.

RESULTS

Differential expression analysis revealed 10 significantly dysregulated miRNAs associated with invasive capacity (Student's t-tests; P value <0.05; fold change = ±2). The expression of top upregulated miR-135b and downregulated let-7c miRNAs correlated with the invasive abilities of eight pancreatic cancer cell lines and displayed differential expression in pancreatic cancer and adjacent normal tissue specimens. Ectopic overexpression of let-7c decreased proliferation, invasion, and colony formation. Integrated analysis of miRNA-mRNA using in silico algorithms and experimental validation databases identified four putative gene targets of let-7c. One of these targets, SOX13, was found to be upregulated in PDAC tumour compared with normal tissue in TCGA and an independent data set by qPCR and immunohistochemistry. RNAi knockdown of SOX13 reduced the invasion and colony formation ability of pancreatic cancer cells.

CONCLUSION

The identification of key miRNA-mRNA gene interactions and networks provide potential diagnostic and therapeutic strategies for better treatment options for pancreatic cancer patients.

Abstract PO-028: Could pharmacodynamic modelling of FOLFIRINOX lead to more therapeutically advantageous treatment of pancreatic cancer?

Pancreatic cancer is one of the most fatal human cancers with a 5-year survival rate of approximately 6%. Pancreatic Ductal Adenocarcinoma (PDAC) is the predominant (~90%) histological type among pancreatic cancers. The poor prognosis of PDAC is due to a combination of factors including late stage diagnosis at a locally advanced or metastatic stage, due to its asymptomatic progression. PDAC is a highly chemoresistant malignancy owing to its genetic heterogeneity and dense stromal environment. FOLFIRINOX (FFX) is a combinatorial chemotherapeutic approach consisting of 5-Fluorouracil (5-FU)/Leucovorin (LV), Irinotecan and Oxaliplatin, and is a first-line treatment option for pancreatic cancer patients. Despite its superior clinical benefit for the treatment of metastatic PDAC compared to gemcitabine, its high toxicity profile limits its use to patients with high performance status. In-depth pharmacodynamic (PD) modelling of the interactions between the individual agents of the regimen is required. Here, the effect of the FFX regime was investigated using both established and primary pancreatic cancer cell-lines cultured as 2D and 3D models. Cells were exposed to a concentration range of each agent in single, double and triple combinations. Cell viability assayed after 5 days. The addition of LV to 5-FU had no effect in vitro in Panc-1, Mia-PaCa-2 and primary PT99 cells, and was excluded from further analysis. The active metabolite of Irinotecan, SN-38, was used in-vitro. The Bliss Independent method was used to fit the cell viability data for all cell lines using SAS 9.4 software. A psi value less than 1 suggests synergistic interactions. Of 4 cell lines tested, MIA-PaCa-2 cells were the most sensitive to the agents of the FFX regimen, with the triple combination demonstrating synergistic interactions with a psi value of 0.036. However, in Panc-1, BxPC-3 and PT127 cells the triple combination was antagonistic, with psi values of 5.167, 3.598 and 5.349 respectively. For the double combination, Ox + SN-38 was shown to have synergistic interactions in 3 of 4 cell lines. The 5-FU + SN-38 and 5-FU + Ox combinations were synergistic in 3 of 4 cell lines. The differences in cellular response observed between the cell lines mirrors the heterogeneity of patients in the clinic and highlights the importance of mathematical modelling to better understand the PD interactions of multidrug treatment regimens. While the triple combinations were determined as antagonistic, meaning the net effect is less than the additive effect of individual agents, it still resulted in greater cell kill than any agent alone. Therefore despite findings of antagonism this further supports the need for all 3 drugs. In conclusion, the results suggest a complex interplay between the three agents, and the PD data could be used to assess whether lower doses and/or alternate dosing schedules would be feasible. This potentially translatable finding may result in FFX being available to more PDAC patients.

Citation Format: Taylor Allen-Coyle, Jin Niu, Eva Welsch, Fiona O'Neill, Martin Clynes, Finbarr O'Sullivan, Donald E. Mager, Robert M. Straubinger, Sandra Roche. Could pharmacodynamic modelling of FOLFIRINOX lead to more therapeutically advantageous treatment of pancreatic cancer? [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2020 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2020;80(22 Suppl):Abstract nr PO-028.

Gene expression profiling of copper-resistant Caco-2 clones

The Caco-2 cell line is composed of a heterogeneous mix of cells; isolation of individual clonal populations from this mix allows for specific mechanisms and phenotypes to be further explored. Previously we exposed Caco-2 cells to inorganic copper sulphate or organic copper proteinate to generate resistant variant populations. Here we describe the isolation and characterisation of clonal subpopulations from these resistant variants to organic (clone Or1, Or2, Or3) or inorganic (clone In1 and In2) copper. The clones show considerable homogeneity in response to Cu-induced toxicity and heterogeneity in morphology with variations in level of cross-resistance to other metals and doxorubicin. Population growth was reduced for Cu-resistant clones In2 and Or3 in selective pressure relative to parental Caco-2 cells. Gene expression analysis identified 4026 total (2102 unique and 1924 shared) differentially expressed genes including those involved in the MAP Kinase and Rap1 signalling pathways, and in the focal adhesion and ECM-receptor contact pathways. Gene expression changes common to all clones included upregulation of ANXA13 and GPx2. Our analysis additionally identified differential expression of multiple genes specific to copper proteinate exposure (including overexpressed UPK1B) in isolated clones Or1, Or2 and Or3 and CuSO4 exposure (including decreased AIFM2 expression) in isolated clones In1 and In2. The adaptive transcriptional responses established in this study indicate a cohort of genes, which may be involved in copper resistance regulation and chronic copper exposure.

Abstract 1678: Establishment and characterization by expression microarrays of a patient-derived xenograft biobank for human pancreatic adenocarcinoma

Pancreatic cancer survival rate is poor, with a 5-year survival rate of 7% in the Republic of Ireland. Over the last 40 years, pancreatic cancer is one of the only solid tumor types to have minimal improvement in patient outcome. In Ireland, pancreatic cancer surgical resection is limited to two hospitals: Cork University Hospital and St Vincent's University Hospital (SVUH) in Dublin. In collaboration with SVUH, we have established Ireland's only pancreatic cancer patient-derived xenograft (PDX) biobank program. Tumor material from candidate patients following surgical resection was cold transferred and implanted subcutaneously into CB17/Icr-Prkdcscid mice. At time of implant and continuation of generations, snap frozen material was collected. Using miRNA and mRNA microarray technology, matched adjacent normal tissue, original tumor material and first generation (F1) PDX tumor material was interrogated. Differential expression analysis was carried out on all samples with comparisons of normal, tumor and F1 generation. Across all comparisons there were approximately 4000 genes and miRNAs found to be differential expressed. In focusing on genes that were upregulated in tumor samples compared to normal and further upregulated in the PDX F1 samples compared to the tumor samples, we identified 88 genes of interest. Biological processes such as cell division, mitotic cell cycle processes and cell cycle processes characterized a significant number of these genes. Two of the key genes of interest in this analysis were TSPAN1 and TPX2. TSPAN1 was upregulated 9.5-fold in tumor-normal comparison and upregulated a further 2.3-fold in the PDX F1 compared to the patient tumor. TPX2 was upregulated 4.4-fold in the tumor-normal comparison and a further 3.9-fold increase in the PDX tumor compared to patient tumor. TSPAN1 has previously been shown to increase the metastatic and invasive potential of pancreatic ductal adenocarcinoma cell lines. TPX2, a microtubule-associated protein, has been shown to reduce tumor growth in vivo when silenced. The pancreatic PDX biobank represents a versatile, expandable patient cohort for preclinical investigation. Analysis of gene expression profiles of normal vs tumor and tumor Vs PDX showed genes with associated tumor proliferation and aggressiveness.

Citation Format: Sandra Roche, Fiona O'Neill, Niall Swan, Ninfa L. Straubinger, Neil T. Conlon, Jean Murphy, Kevin Conlon, Ray McDermott, Justine Meiller, Justin Geoghegan, Michael Moriarty, Robert M. Straubinger, Martin Clynes. Establishment and characterization by expression microarrays of a patient-derived xenograft biobank for human pancreatic adenocarcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1678.

Identifying and exploring linguistic expertise of psychiatrists in interviews with patients with thought disorder

OBJECTIVE

To identify and understand the linguistic expertise of psychiatrists in clinical interviews with patients experiencing thought disorder (TD).

METHOD

Qualitative analysis of 24 routine clinical interviews between psychiatrists and inpatients with TD.

RESULTS

Psychiatrists demonstrated the expertise with which they navigated clinical interviews and accomplished shared goals with patients experiencing TD. These findings highlight the need to rethink the notion that such patients are incapable of productive communication. Capturing and describing psychiatrists' tacit expertise provides a foundation for documenting an under-recognised skill set.

CONCLUSIONS

Understanding such expertise could enhance the care of patients with TD, repositioning them as active participants in the accomplishment of shared therapeutic goals. Teaching these skills to mental health clinicians during their training would improve their ability to establish effective therapeutic relationships with these patients.

Altered gene expression in CHO cells following polyamine starvation

AIM

To investigate the impact of polyamine deprivation on the transcriptome of CHO cells RESULTS: Polyamines play a central but poorly-understood role in cell proliferation. Most studies to date have utilised chemical inhibitors to probe polyamine function. Here we exploit the fact that CHO cells grown in serum-free medium have an absolute requirement for putrescine supplementation due to their deficiency in activity of the enzyme arginase. A gene expression microarray (Affymetrix) analysis of CHO-K1 cells starved of polyamines for 3 days showed that cessation of growth, associated with increased G1/S transition and inhibition of M/G1 transition was accompanied by increased mRNA levels of mitotic complex checkpoint genes (Mad2l1, Tkk, Bub1b) and in the transition of G1- to S-phase (such as Skp2 and Tfdp1). mRNAs associated with DNA homologous recombination and repair (including Fanconi's anaemia-related genes) and with RNA splicing were consistently increased. Alterations in mRNA levels for genes related to protein processing in the ER, to ER stress, and to p53-related and apoptosis pathways were also observed. mRNAs showing highest levels of fold-change included several which code for membrane-localised proteins and receptors (Thbs1, Tfrc1, Ackr3, Extl1).

CONCLUSIONS

Growth-arrest induced by polyamine deprivation was associated with significant alterations in levels of mRNAs associated with cell cycle progression, DNA repair, RNA splicing, ER trafficking and membrane signalling as well as p53 and apoptosis-related pathways.

Modelling of pancreatic cancer biology: transcriptomic signature for 3D PDX-derived organoids and primary cell line organoid development

With a five-year survival rate of 9%, pancreatic ductal adenocarcinoma (PDAC) is the deadliest of all cancers. The rapid mortality makes PDAC difficult to research, and inspires a resolve to create reliable, tractable cellular models for preclinical cancer research. Organoids are increasingly used to model PDAC as they maintain the differentiation status, molecular and genomic signatures of the original tumour. In this paper, we present novel methodologies and experimental approaches to develop PDAC organoids from PDX tumours, and the simultaneous development of matched primary cell lines. Moreover, we also present a method of recapitulating primary cell line cultures to organoids (CLOs). We highlight the usefulness of CLOs as PDAC organoid models, as they maintain similar transcriptomic signatures as their matched patient-derived organoids and patient derived xenografts (PDX)s. These models provide a manageable, expandable in vitro resource for downstream applications such as high throughput screening, functional genomics, and tumour microenvironment studies.

KH-Type Splicing Regulatory Protein Controls Colorectal Cancer Cell Growth and Modulates the Tumor Microenvironment

KH-type splicing regulatory protein (KHSRP) is a multifunctional nucleic acid binding protein implicated in key aspects of cancer cell biology: inflammation and cell-fate determination. However, the role KHSRP plays in colorectal cancer (CRC) tumorigenesis remains largely unknown. Using a combination of in silico analysis of large data sets, ex vivo analysis of protein expression in patients, and mechanistic studies using in vitro models of CRC, we investigated the oncogenic role of KHSRP. We demonstrated KHSRP expression in the epithelial and stromal compartments of both primary and metastatic tumors. Elevated expression was found in tumor versus matched normal tissue, and these findings were validated in larger independent cohorts in silico. KHSRP expression was a prognostic indicator of worse overall survival (hazard ratio, 3.74; 95% CI, 1.43-22.97; P = 0.0138). Mechanistic data in CRC cell line models supported a role of KHSRP in driving epithelial cell proliferation in both a primary and metastatic setting, through control of the G₁/S transition. In addition, KHSRP promoted a proangiogenic extracellular environment by regulating the secretion of oncogenic proteins involved in diverse cellular processes, such as migration and response to cellular stress. Our study provides novel mechanistic insight into the tumor-promoting effects of KHSRP in CRC.

Abstract 44: Assessment of pancreatic cancer 3D organotypic cultures as models for functional preclinical analysis

Pancreatic ductal adenocarcinoma (PDAC) is the deadliest of all cancers, with a five-year survival rate of 8%. Decades of research has done little to improve patient outcomes. To identify key therapeutic strategies, appropriate research preclinical models are critical for testing the efficacy of drugs or downstream functional genomic analysis. Current methods of growing PDAC established cell lines in a 2D monolayer do not fully represent how the tumor cells grow in vivo as they fail to recapitulate the physiology of tumors in vivo due to different architecture, adherence structures and biochemical gradients. Patient-derived xenografts can retain the histological and genetic characteristics of their donor tumor and can remain stable across passages. Three-dimensional (3D) organoids grown ex vivo are tractable also retain the architecture, genotype and phenotype of a patients’ tumor.

However, a detailed comparative assessment of the utility of organoids, matched 2D cell lines and 3D cell organotypic models to assess the complex biology, interactions, response to therapeutic regimens has not been performed.

Using our unique protocol, we have established PDAC organoids and isogenetically matched 2D cell lines derived from PDAC PDX tumors. To establish if these matched 2D cell lines grown in 3D can recapitulate the organoid model, we cultured the matched cell lines in 3D organoid media in non-adherent, Matrigel containing cultures. The expression of PDAC histological markers between the original tumor, the PDX tumor, organoid and matched cell line in 3D and 2D has identified differential expression of tumor initiating cell (TIC) markers. RNA-seq transcriptomics of the 2D cell line models, matched recapitulated 3D organotypic models, organoids, PDX-tumor and patient tumor will reveal the application of these models for ex vivo downstream functional analysis.

Citation Format: Shannon R. Nelson, Sandra Roche, Fiona O'Neill, AnneMarie Larkin, John Crown, Naomi Walsh. Assessment of pancreatic cancer 3D organotypic cultures as models for functional preclinical analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 44.

Abstract P5-03-02: Pre-clinical investigation of PP2A inhibitor LB-100 in overcoming and preventing lapatinib resistance in HER2-positive breast cancer

Background: HER2-positive breast cancer (BC) accounts for approximately 15% of all BC. HER2-targeted therapies, such as trastuzumab and lapatinib, have significantly improved the outcome for these patients. However, HER2-targeted therapy resistance is a common clinical issue. We have previously shown that protein phosphatase 2A (PP2A) plays a role in mediating acquired lapatinib resistance in HER2-positive BC and that response to lapatinib is enhancedin vitroby the lab-grade PP2A inhibitor, okadaic acid. The aim of this study was to examine the in vitro and in vivo efficacy of LB-100, a PP2A inhibitor that has completed phase I clinical testing (NCT01837667), in models of HER2-positive BC with acquired resistance to lapatinib.

Methods: HER2-positiveSKBR3 and HCC1954 BC cell lines were treated with 250 nM or 1 μM lapatinib, respectively, for 6 months to generate lapatinib-resistant SKBR3-L and HCC1954-L cell lines. In vitro sensitivity to lapatinib and LB-100 was assessed by 2D acid phosphatase assay. Combination index (CI) values were generated to identify synergistic combinations. Propidium iodide staining was used to determine cell cycle arrest and apoptosis. In order to examine the in vivo efficacy of LB-100, HCC1954-L cells were implanted into the mammary fat pad of BALB/c nude mice and treated with vehicle, lapatinib, LB-100, or lapatinib plus LB-100. To examine the prevention of the development of lapatinib resistance, SKBR3 and HCC1954 cells were treated twice weekly with lapatinib, LB-100 or the combination and stained with crystal violet when confluent.

Results: SKBR3-L and HCC1954-L cells were resistant to lapatinib at clinically relevant concentrations (IC50values = 2.37 ± 0.58 μM and 1.67 ± 0.34 μM). This represents a 46- and 5.2-fold decrease in lapatinib sensitivity. LB-100 had a greater anti-proliferative effect in the lapatinib-resistant SKBR3-L and HCC1954-L cell lines compared to their respective parental cell lines (IC50values = 2.12 ± 0.2 μM v 5.38 ± 0.6 μM, and 2.31 ± 0.19 μM v 5.32 ± 0.82 μM, respectively). LB-100 overcame lapatinib resistance in both models, as lapatinib plus LB-100 was synergistic in both cell lines (CI values = 0.56 ± 0.13 and 0.68 ±0.26). LB-100 caused cell death through the induction of apoptosis in SKBR3- L (p = 0.019) and HCC1954-L (p = 0.046) and the addition of lapatinib to LB-100 increased apoptotic induction in HCC1954-L cells (p=0.046).Lapatinib plus LB-100 was well tolerated in vivo. The HCC1954-L cell line maintained resistance to lapatinib in vivo and the combination of lapatinib and LB-100 significantly reduced HCC1954-L tumour volume compared to all other treatment arms (p = 0.0006). Interestingly, in vitro short-term resistance assays showed that the addition of LB-100 to lapatinib could also block the emergence of lapatinib resistance in both parental SKBR3 and HCC1954 cell lines.

Conclusions: This study indicates that LB-100 has in vitro and in vivo efficacy against lapatinib-resistant HER2-positive BC cell line models and justifies further investigation into its potential to circumvent or prevent lapatinib resistance in HER2-positive BC.

Citation Format: Conlon N, McDermott M, Browne B, Roche S, O'Neill F, Meiller J, Browne A, Eustace A, Collins DM, O'Donovan N, Crown J. Pre-clinical investigation of PP2A inhibitor LB-100 in overcoming and preventing lapatinib resistance in HER2-positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-03-02.

A Comparative Quantitative LC-MS/MS Profiling Analysis of Human Pancreatic Adenocarcinoma, Adjacent-Normal Tissue, and Patient-Derived Tumour Xenografts

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers worldwide; it develops in a relatively symptom-free manner, leading to rapid disease progression and metastasis, leading to a 5-year survival rate of less than 5%. A lack of dependable diagnostic markers and rapid development of resistance to conventional therapies are among the problems associated with management of the disease. A better understanding of pancreatic tumour biology and discovery of new potential therapeutic targets are important goals in pancreatic cancer research. This study describes the comparative quantitative LC-MS/MS proteomic analysis of the membrane-enriched proteome of 10 human pancreatic ductal adenocarcinomas, 9 matched adjacent-normal pancreas and patient-derived xenografts (PDXs) in mice (10 at F1 generation and 10 F2). Quantitative label-free LC-MS/MS data analysis identified 129 proteins upregulated, and 109 downregulated, in PDAC, compared to adjacent-normal tissue. In this study, analysing peptide MS/MS data from the xenografts, great care was taken to distinguish species-specific peptides definitively derived from human sequences, or from mice, which could not be distinguished. The human-only peptides from the PDXs are of particular value, since only human tumour cells survive, and stromal cells are replaced during engraftment in the mouse; this list is, therefore, enriched in tumour-associated proteins, some of which might be potential therapeutic or diagnostic targets. Using human-specific sequences, 32 proteins were found to be upregulated, and 113 downregulated in PDX F1 tumours, compared to primary PDAC. Differential expression of CD55 between PDAC and normal pancreas, and expression across PDX generations, was confirmed by Western blotting. These data indicate the value of using PDX models in PDAC research. This study is the first comparative proteomic analysis of PDAC which employs PDX models to identify patient tumour cell-associated proteins, in an effort to find robust targets for therapeutic treatment of PDAC.

Abstract C20: Investigating the role of the tumor microenvironment and its role in radiation therapy in pancreatic cancer

Pancreatic cancer is the 10th most common cancer in Ireland and the 5th most common cause of death. The 5 year survival rate is approximately 6%, due to late diagnosis by which time usually metastasis has occurred. Despite an increase in research on the disease in recent years very little progress has been made and the development of new, more effective therapies is needed.

The role of the tumor microenvironment in the progression of pancreatic cancer is becoming the focus of more and more research. It has been determined that the tumor microenvironment plays a significant role in the progression and invasion of the cancer cells and also plays a role in the resistance of tumor to therapy.

Utilizing established pancreatic cell lines and human derived fibroblasts and stellate cells, an indirect co-culture approach has been utilized to investigate the mechanisms by which the fibroblasts and stellate cells in the tumor influence the behavior of the cancer cells.

Using the same indirect co-culture approach we have sought to evaluate the role in which these stromal components have in the tumor cells response to radiation therapy. We have utilized single and fractionated doses to determine if the different approaches have varying effects on the proliferation, invasion and colony forming ability of the cancer cells.

It is hoped that this in vitro evaluation could be used to inform a better approach to radiation treatment of pancreatic cancer.

Citation Format: Fiona O'Neill, Gemma Moore, Serena O'Keeffe, Brendan McClean, Gerard McVey, Michael Moriarty, Laura Breen, Martin Clynes. Investigating the role of the tumor microenvironment and its role in radiation therapy in pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C20.

Comparison of single CT scan assessment of bone mineral density, vascular calcification and fat mass with standard clinical measurements in renal transplant subjects: the ABC HeART study

Background

Despite limitations of routine methods, Clinical Practice Guidelines support the assessment of bone mineral density (BMD) and vascular calcification in renal transplant recipients. Changes in fat mass also occur post-transplantation, although they are traditionally difficult to measure accurately. We report the feasibility, convenience and accuracy of measuring the above 3 parameters using a novel CT protocol.

Methods

We conducted a cross-sectional study of 64 first renal allograft recipients (eGFR > 30 ml/min/1.73 m²). Quantitative CT (QCT) BMD analysis was conducted using CT lumbar spine (GE Medical Systems Lightspeed VCT & Mindways QCT Pro Bone Mineral Densitometry System Version 4.2.3) to calculate spinal volumetric BMD and compared with standard DXA calculated areal BMD at the spine, hip and distal forearm. Abdominal aortic calcification was assessed by semi-quantitative Aortic Calcification Index (ACI) method and compared with lateral lumbar x-ray Kappuila score and pulse wave velocity (PWV). Visceral and subcutaneous adipose tissue volume (Osirix 16 Ver 3.7.1) was compared with BMI.

Results

Participants were 61 % male, had a mean age of 47 years, median ESKD duration of 5.4 years and a mean eGFR of 54 ml/min. iDXA median T-score at proximal femur was −1.2 and at lumbar spine was −0.2. Median QCT Trabecular T-score at lumbar spine was −1.2. The percent of subjects with a T-score of <2.5 by site and method was DXA Proximal Femur: 7 %, DXA distal radius: 17 %, DXA spine: 9 %, QCT (American College of Radiology cutoffs): 9 %. CT derived ACI correlated with PWV (r = 0.29, p = 0.02), pulse wave pressure (r = 0.51, p < 0.001), QCT Trabecular (−0.31, p = 0.01) and cortical volumetric BMD and history of cardiovascular events (Mann–Whitney U, p = 0.02). Both visceral and subcutaneous adipose tissue correlated with BMI (r = 0.63 & 0.64, p < 0.001).

Conclusions

Single CT scan triple assessment of BMD, vascular calcification and body composition is an efficient, accurate and convenient method of risk factor monitoring post renal transplantation.

Ethics in research: practice and respect

Nursing practice is informed by research, and all nurses, midwives and care staff should be research aware even if they do not consider themselves research active. The principles of research ethics, based on respect for individuals, should not be confined to research. All nurses must be aware of these principles, and practise in accordance with them.

Non-contrast CT at comparable dose to an abdominal radiograph in patients with acute renal colic; impact of iterative reconstruction on image quality and diagnostic performance

OBJECTIVES

The aim was to assess the performance of low-dose non-contrast CT of the urinary tract (LD-CT) acquired at radiation exposures close to that of abdominal radiography using adaptive statistical iterative reconstruction (ASiR).

METHODS

Thirty-three patients with clinically suspected renal colic were prospectively included. Conventional dose (CD-CT) and LD-CT data sets were contemporaneously acquired. LD-CT images were reconstructed with 40 %, 70 % and 90 % ASiR. Image quality was subjectively and objectively measured. Images were also clinically interpreted.

RESULTS

Mean ED was 0.48 ± 0.07 mSv for LD-CT compared with 4.43 ± 3.14 mSv for CD-CT. Increasing the percentage ASiR resulted in a step-wise reduction in mean objective noise (p < 0.001 for all comparisons). Seventy % ASiR LD-CT images had higher diagnostic acceptability and spatial resolution than 90 % ASiR LD-CT images (p < 0.001). Twenty-seven calculi (diameter = 5.5 ± 1.7 mm), including all ureteric stones, were correctly identified using 70 % ASiR LD-CT with two false positives and 16 false negatives (diameter = 2.3 ± 0.7 mm) equating to a sensitivity and specificity of 72 % and 94 %. Seventy % ASiR LD-CT had a sensitivity and specificity of 87 % and 100 % for detection of calculi >3 mm.

CONCLUSION

Reconstruction of LD-CT images with 70 % ASiR resulted in superior image quality than FBP, 40 % ASIR and 90 % ASIR. LD-CT with ASIR demonstrates high sensitivity and specificity for detection of calculi >3 mm.

TEACHING POINTS

• Low-dose CT studies for urinary calculus detection were performed with a mean dose of 0.48 ± 0.07 mSv • Low-dose CT with 70 % ASiR detected calculi >3 mm with a sensitivity and specificity of 87 % and 100 % • Reconstruction with 70 % ASiR was superior to filtered back projection, 40 % ASiR and 90 % ASiR images.

Determination of the Proteomic Response to Lapatinib Treatment using a comprehensive and reproducible ion-current-based proteomics strategy

Lapatinib, a small molecule tyrosine kinase inhibitor is currently used in the treatment of HER2-positive breast cancer. The aim of this study was to further understanding of lapatinib response for the development of novel treatment lapatinib-focussed treatment strategies. HER2-overexpressing SKBR3 breast cancer cells were treated with lapatinib for 12 hours and the resultant proteome analyzed by a comprehensive ion-current-based LC-MS strategy. Among the 1224 unique protein identified from SKBR3 cell lysates, 67 showed a significant change in protein abundance in response to lapatinib. Of these, CENPE a centromeric protein with increased abundance, was chosen for further validation. Knockdown and inhibition of CENPE demonstrated that CENPE enhances SKBR3 cell survival in the presence of lapatinib. Based on this study, CENPE inhibitors may warrant further investigation for use in combination with lapatinib.

A gene expression profile indicative of early stage HER2 targeted therapy response

Background

Efficacious application of HER2-targetting agents requires the identification of novel predictive biomarkers. Lapatinib, afatinib and neratinib are tyrosine kinase inhibitors (TKIs) of HER2 and EGFR growth factor receptors. A panel of breast cancer cell lines was treated with these agents, trastuzumab, gefitinib and cytotoxic therapies and the expression pattern of a specific panel of genes using RT-PCR was investigated as a potential marker of early drug response to HER2-targeting therapies.

Results

Treatment of HER2 TKI-sensitive SKBR3 and BT474 cell lines with lapatinib, afatinib and neratinib induced an increase in the expression of RB1CC1, ERBB3, FOXO3a and NR3C1. The response directly correlated with the degree of sensitivity. This expression pattern switched from up-regulated to down-regulated in the HER2 expressing, HER2-TKI insensitive cell line MDAMB453. Expression of the CCND1 gene demonstrated an inversely proportional response to drug exposure. A similar expression pattern was observed following the treatment with both neratinib and afatinib. These patterns were retained following exposure to traztuzumab and lapatinib plus capecitabine. In contrast, gefitinib, dasatinib and epirubicin treatment resulted in a completely different expression pattern change.

Conclusions

In these HER2-expressing cell line models, lapatinib, neratinib, afatinib and trastuzumab treatment generated a characteristic and specific gene expression response, proportionate to the sensitivity of the cell lines to the HER2 inhibitor.

Characterisation of the induced changes in expression levels of these genes may therefore give a valuable, very early predictor of the likely extent and specificity of tumour HER2 inhibitor response in patients, potentially guiding more specific use of these agents.

A prospective feasibility study of sub-millisievert abdominopelvic CT using iterative reconstruction in Crohn's disease

OBJECTIVE

Iterative reconstruction (IR) allows diagnostic CT imaging with less radiation exposure than filtered back projection (FBP). We studied an IR low-dose CT abdomen/pelvis (LDCTAP) protocol, designed to image at an effective dose (ED) approximating 1 mSv in patients with Crohn's disease (CD).

METHODS

Forty patients, mean age 37 ± 13.4 years (range 17-69), with CD underwent two synchronous CT protocols (conventional-dose (CDCTAP) and LDCTAP). CDCTAP and LDCTAP images were compared for diagnostic acceptability, yield, image quality and ED (in millisieverts). The optimal level of IR for LDCTAP was also studied.

RESULTS

LDCTAP yielded a mean ED of 1.3 ± 0.8 mSv compared with 4.7 ± 2.9 mSv for CDCTAP, reducing ED by 73.7 ± 3.3 % (mean dose reduction, 3.5 ± 2.1 mSv; P < 0.001) and dose length product by 73.6 ± 2.6 % (P < 0.001). Sub-millisievert (0.84 mSv) imaging was performed for patients with a body mass index (BMI) less than 25 (i.e. 63 % of our cohort). LDCTAP resulted in increased image noise and reduced diagnostic acceptability compared with CDCTAP despite use of IR, but detection of extra-luminal complications was comparable.

CONCLUSION

Patients with suspected active CD can be adequately imaged using LDCTAP, yielding comparable information regarding extent, activity and complications of CD compared with CDCTAP, but with 74 % less dose. LDCTAP at doses equivalent to that of two abdominal radiographs represents a feasible alternative to CDCTAP.

KEY POINTS

• Radiation dose is a concern when imaging patients with Crohn's disease. • New techniques allow low-dose abdominopelvic CT with acceptable image quality. • Using hybrid iterative reconstruction, its diagnostic yield compares well with that of conventional CT. • Sub-millisievert CT of patients with Crohn's disease appears technically and clinically feasible.

Influence of implant design on the method of failure for three implants designed for use in the treatment of intertrochanteric fractures: the dynamic hip screw (DHS), DHS blade and X-BOLT

BACKGROUND

The dynamic hip screw (DHS) has been widely adopted as the implant of choice in the treatment of intertrochanteric fractures. There have been attempts over the years to improve on the DHS lag screw design in order to reduce failure in the form of "cut out". The purpose of this study was to investigate how two new design variations of the DHS, the DHS blade and the X-BOLT, behave within bone, and if these design modifications do indeed improve the fixation achieved and lead to a reduction in failure due to cut out.

METHODS

"Pushout" tests were chosen as the means of investigating the failure modes and patterns for these implants that lead to cut out. These pushout studies were performed in artificial bone substrate in the form of polyurethane foam blocks and in cadaveric femoral heads.

RESULTS

The results demonstrated that each individual implant produces its own specific distinct force-displacement curve or pattern of failure, and that despite the very different implant designs and methods of fixation, all of the implants tested reached very similar peak forces in each of the test materials used.

CONCLUSION

The results demonstrated that implant design only influences the pattern of failure, and that the peak forces reached by each implant are determined by the quality of the bone or test material into which they are placed. However, altering the force-displacement curve or pattern of failure may be enough to improve the fixation achieved and to provide an increased resistance to cut out.

A gene expression profile indicative of early stage HER2 tyrosine kinase inhibitor response

e11536

Background: Lapatinib, afatinib and neratinib are tyrosine kinase inhibitors (TKIs) of HER2 and EGFR growth receptors. A panel of breast cancer cell lines was treated with these agents and gefintib (EGFR inhibitor) and the expression pattern of a specific panel of genes investigated as a potential marker of early drug response. Methods: RNA was extracted from breast cancer cell lines (BT474, SKBR3 and MDAMB453) with differing HER2 expression patterns and sensitivity to lapatinib before and 12hrs after treatment with 1 µM of lapatinib, 150nM of afatinib, 150nM of neratinib or 1µM of gefitinib. Gene expression changes were measured by Taqman RT-PCR and RQ values were determined using the comparative cycle threshold (Ct) method. Results: The expression of RB1CC1, ERBB3, FOXO3a, NR3C1 was directly correlated with the degree of sensitivity of the cell line to lapatinib and was observed to “switch” from up-regulated to down-regulated in the HER2 expressing lapatinib insensitive cell line (MDAMD453). The CCND1 gene (functionally linked to the other four genes) demonstrated an inversely proportional response to drug exposure; showing a trend of strong down-regulation in lapatinib-sensitive lines. A similar expression pattern was observed following the treatment with both neratinib and afatinib. In contrast, gefitinib treatment, resulted in a completely different expression pattern change. Conclusions: In these HER2-expressing cell models, lapatinib, neratinib and afatinib treatment generated a common, characteristic and specific gene expression response, proportionate to the sensitivity of the cell lines to the HER2 inhibitor. Characterisation of changes in these genes shortly after drug treatment may therefore give a valuable predictor of the likely extent and specificity of tumour HER2 inhibitor response in patients, potentially guiding more specific use of these agents.

Pelvic and acetabular fractures

Patients that sustain pelvic and/or acetabular trauma in Ireland and require surgical intervention are treated at the Adelaide and Meath National Children's Hospital (AMNCH). For this study an audit was conducted of all pelvic and acetabular fractures referred to the AMNCH over a 12 month period from July 2010 to June 2011. This study was conducted with the purpose of recording the different fracture patterns, methods of injury and surgical procedures performed over this time frame. The results demonstrate that 109 patients were referred to the AMNCH with the majority of these fractures being sustained as the result of an RTA (43) or a fall from a height (45). Seventy one patients suffered an acetabular fracture while 43 patients suffered a fracture of their pelvic ring with some patients suffering both. There were 129 surgical procedures performed with 25 patients having more than one surgical procedure.

A bilateral crescent and anterior ring pelvic fracture sustained by inadvertently performing the 'splits'

A case is presented of a healthy 57 year old female who slipped and fell awkwardly into what is known in athletic terms as the front splits. As a result of her fall she sustained bilateral crescent and superior and inferior rami pelvic fractures. Successful operative fixation was undertaken by a combination of open and percutaneous techniques. To our knowledge this is the first reported case of bilateral crescent fractures, and of a pelvic fracture as a result of this mechanism of injury.

Identification of new susceptibility loci for osteoarthritis (arcOGEN): a genome-wide association study

BACKGROUND

Osteoarthritis is the most common form of arthritis worldwide and is a major cause of pain and disability in elderly people. The health economic burden of osteoarthritis is increasing commensurate with obesity prevalence and longevity. Osteoarthritis has a strong genetic component but the success of previous genetic studies has been restricted due to insufficient sample sizes and phenotype heterogeneity.

METHODS

We undertook a large genome-wide association study (GWAS) in 7410 unrelated and retrospectively and prospectively selected patients with severe osteoarthritis in the arcOGEN study, 80% of whom had undergone total joint replacement, and 11,009 unrelated controls from the UK. We replicated the most promising signals in an independent set of up to 7473 cases and 42,938 controls, from studies in Iceland, Estonia, the Netherlands, and the UK. All patients and controls were of European descent.

FINDINGS

We identified five genome-wide significant loci (binomial test p≤5·0×10(-8)) for association with osteoarthritis and three loci just below this threshold. The strongest association was on chromosome 3 with rs6976 (odds ratio 1·12 [95% CI 1·08-1·16]; p=7·24×10(-11)), which is in perfect linkage disequilibrium with rs11177. This SNP encodes a missense polymorphism within the nucleostemin-encoding gene GNL3. Levels of nucleostemin were raised in chondrocytes from patients with osteoarthritis in functional studies. Other significant loci were on chromosome 9 close to ASTN2, chromosome 6 between FILIP1 and SENP6, chromosome 12 close to KLHDC5 and PTHLH, and in another region of chromosome 12 close to CHST11. One of the signals close to genome-wide significance was within the FTO gene, which is involved in regulation of bodyweight-a strong risk factor for osteoarthritis. All risk variants were common in frequency and exerted small effects.

INTERPRETATION

Our findings provide insight into the genetics of arthritis and identify new pathways that might be amenable to future therapeutic intervention.

FUNDING

arcOGEN was funded by a special purpose grant from Arthritis Research UK.

Diagnostic accuracy of computed tomography using lower doses of radiation for patients with Crohn's disease

BACKGROUND & AIMS

Magnetic resonance and ultrasonography have increasing roles in the initial diagnosis of Crohn's disease, but computed tomography (CT) with positive oral contrast agents is most frequently used to identify those with acute extramural complications. However, CT involves exposure of patients to radiation. We prospectively compared the diagnostic accuracy of low-dose CT (at a dose comparable to that used to obtain an abdominal radiograph) with conventional-dose CT in patients with active Crohn's disease.

METHODS

Low and conventional dose CT of the abdomen and pelvis were acquired from 50 patients with Crohn's disease, referred from an inflammatory bowel disease service (20 male; median age, 34 years). Acute complications of Crohn's disease were suspected. Iterative reconstruction was performed on all CT datasets to facilitate dose reduction. Three radiologists reviewed the low-dose CT images before the conventional-dose CT images.

RESULTS

The median effective dose (interquartile range) of radiation for the low-dose CT was reduced by 72% from that of conventional CT: from 3.5 mSv (3-5.08 mSv) to 0.98 mSv (0.77-1.42 mSv) (P < .001). As expected, the quality indexes of the low-dose images were inferior to those of the conventional-dose images, but no clinically significant diagnostic findings were missed with low-dose imaging. Follow-up CT examinations were recommended for 5 patients; 1 had a cervical tumor, 1 had a pancreatic lesion, and 3 had intra-abdominal abscess. In each case, the image obtained by low-dose CT was considered sufficient for diagnosis.

CONCLUSIONS

Although low-dose CT images are of lower quality than images obtained with conventional doses of radiation, no clinically significant diagnostic findings were missed from low-dose CT images of patients with Crohn's disease. The low-dose CT was obtained at a median effective dose equivalent to 1.4 abdominal radiographs.

Gene expression changes as markers of early lapatinib response in a panel of breast cancer cell lines

Background

Lapatinib, a tyrosine kinase inhibitor of HER2 and EGFR and is approved, in combination with capecitabine, for the treatment of trastuzumab-refractory metastatic breast cancer. In order to establish a possible gene expression response to lapatinib, a panel of breast cancer cell lines with varying sensitivity to lapatinib were analysed using a combination of microarray and qPCR profiling.

Methods

Co-inertia analysis (CIA), a data integration technique, was used to identify transcription factors associated with the lapatinib response on a previously published dataset of 96 microarrays. RNA was extracted from BT474, SKBR3, EFM192A, HCC1954, MDAMB453 and MDAMB231 breast cancer cell lines displaying a range of lapatinib sensitivities and HER2 expression treated with 1 μM of lapatinib for 12 hours and quantified using Taqman RT-PCR. A fold change ≥ ± 2 was considered significant.

Results

A list of 421 differentially-expressed genes and 8 transcription factors (TFs) whose potential regulatory impact was inferred in silico, were identified as associated with lapatinib response. From this group, a panel of 27 genes (including the 8 TFs) were selected for qPCR validation. 5 genes were determined to be significantly differentially expressed following the 12 hr treatment of 1 μM lapatinib across all six cell lines. Furthermore, the expression of 4 of these genes (RB1CC1, FOXO3A, NR3C1 and ERBB3) was directly correlated with the degree of sensitivity of the cell line to lapatinib and their expression was observed to “switch” from up-regulated to down-regulated when the cell lines were arranged in a lapatinib-sensitive to insensitive order. These included the novel lapatinib response-associated genes RB1CC1 and NR3C1. Additionally, Cyclin D1 (CCND1), a common regulator of the other four proteins, was also demonstrated to observe a proportional response to lapatinib exposure.

Conclusions

A panel of 5 genes were determined to be differentially expressed in response to lapatinib at the 12 hour time point examined. The expression of these 5 genes correlated directly with lapatinib sensitivity. We propose that the gene expression profile may represent both an early measure of the likelihood of sensitivity and the level of response to lapatinib and may therefore have application in early response detection.

Validity of synthetic bone as a substitute for osteoporotic cadaveric femoral heads in mechanical testing: A biomechanical study

Introduction

The objective of this study was to determine if a synthetic bone substitute would provide results similar to bone from osteoporotic femoral heads during in vitro testing with orthopaedic implants. If the synthetic material could produce results similar to those of the osteoporotic bone, it could reduce or eliminate the need for testing of implants on bone.

Methods

Pushout studies were performed with the dynamic hip screw (DHS) and the DHS Blade in both cadaveric femoral heads and artificial bone substitutes in the form of polyurethane foam blocks of different density. The pushout studies were performed as a means of comparing the force displacement curves produced by each implant within each material.

Results

The results demonstrated that test material with a density of 0.16 g/cm³ (block A) produced qualitatively similar force displacement curves for the DHS and qualitatively and quantitatively similar force displacement curves for the DHS Blade, whereas the test material with a density of 0.08 g/cm³ (block B) did not produce results that were predictive of those recorded within the osteoporotic cadaveric femoral heads.

Conclusion

This study demonstrates that synthetic material with a density of 0.16 g/cm³ can provide a good substitute for cadaveric osteoporotic femoral heads in the testing of implants. However we do recognise that no synthetic material can be considered as a definitive substitute for bone, therefore studies performed with artificial bone substrates may need to be validated by further testing with a small bone sample in order to produce conclusive results.

Sunlight and dietary contributions to the seasonal vitamin D status of cohorts of healthy postmenopausal women living at northerly latitudes: a major cause for concern?

We assessed sunlight and dietary contributions to vitamin D status in British postmenopausal women. Our true longitudinal 25-hydroxyvitamin D (25(OH)D) measurements varied seasonally, being lower in the north compared to the south and lower in Asian women. Sunlight exposure in summer and spring provided 80% total annual intake of vitamin D.

INTRODUCTION

Vitamin D deficiency is highlighted as a potential problem for countries at high latitude, but there are few true longitudinal, seasonal data to allow regional comparisons. We aimed to directly compare seasonal variation in vitamin D status (25(OH)D) in postmenopausal women at two northerly latitudes and to assess the relative contributions of sunlight exposure and diet.

METHODS

Vitamin D status was assessed in 518 postmenopausal women (age 55-70 years) in a two-centre cohort study with serum collected at fixed three-monthly intervals from summer 2006 for immunoassay measurement of 25(OH)D and parathyroid hormone. At 57° N (Aberdeen, Scotland, UK), there were 338 Caucasian women; at 51° N (Surrey, South of England, UK), there were 144 Caucasian women and 35 Asian women. UVB exposure (polysulphone film badges) and dietary vitamin D intakes (food diaries) were also estimated.

RESULTS

Caucasian women had lower 25(OH)D (p < 0.001) at 57° N compared to 51° N. Median (interquartile range) in nanomoles per litre for summer (June-August) at 57° N was 43.0 (20.9) and at 51° N was 62.5 (26.6) and for winter (December-February) at 57° N was 28.3 (18.9) and at 51° N was 39.9 (24.0). For Asian women at 51° N, median 25(OH)D was 24.0 (15.8) nmol/L in summer and 16.9 (15.9) nmol/L in winter. Median dietary vitamin D intakes were 80-100 IU for Caucasians and 50-65 IU for the Asian women. Sunlight was the main contributor to 25(OH)D with spring and summer providing >80% total annual intake.

CONCLUSIONS

These longitudinal data show significant regional and ethnic differences in UVB exposure and vitamin D status for postmenopausal women at northerly latitudes. The numbers of women who are vitamin D deficient is a major concern and public health problem.

Dynamic hip screw versus DHS blade: a biomechanical comparison of the fixation achieved by each implant in bone

We biomechanically investigated whether the standard dynamic hip screw (DHS) or the DHS blade achieves better fixation in bone with regard to resistance to pushout, pullout and torsional stability. The experiments were undertaken in an artificial bone substrate in the form of polyurethane foam blocks with predefined mechanical properties. Pushout tests were also repeated in cadaveric femoral heads. The results showed that the DHS blade outperformed the DHS with regard to the two most important characteristics of implant fixation, namely resistance to pushout and rotational stability. We concluded that the DHS blade was the superior implant in this study.

Insights into the genetic architecture of osteoarthritis from stage 1 of the arcOGEN study

Objectives

The genetic aetiology of osteoarthritis has not yet been elucidated. To enable a well-powered genome-wide association study (GWAS) for osteoarthritis, the authors have formed the arcOGEN Consortium, a UK-wide collaborative effort aiming to scan genome-wide over 7500 osteoarthritis cases in a two-stage genome-wide association scan. Here the authors report the findings of the stage 1 interim analysis.

Methods

The authors have performed a genome-wide association scan for knee and hip osteoarthritis in 3177 cases and 4894 population-based controls from the UK. Replication of promising signals was carried out in silico in five further scans (44 449 individuals), and de novo in 14 534 independent samples, all of European descent.

Results

None of the association signals the authors identified reach genome-wide levels of statistical significance, therefore stressing the need for corroboration in sample sets of a larger size. Application of analytical approaches to examine the allelic architecture of disease to the stage 1 genome-wide association scan data suggests that osteoarthritis is a highly polygenic disease with multiple risk variants conferring small effects.

Conclusions

Identifying loci conferring susceptibility to osteoarthritis will require large-scale sample sizes and well-defined phenotypes to minimise heterogeneity.

Seasonal 25-hydroxyvitamin D changes in British postmenopausal women at 57 degrees N and 51 degrees N: a longitudinal study

The UK has insufficient intensity of sunlight at wavelengths 290-315 nm to enable cutaneous synthesis of vitamin D from October to April. There are regional differences in UVB strength throughout the UK but whether this translates to differences in vitamin D status is not known. We have reported seasonal variations in a cross-sectional study of over 3000 Scottish women in Aberdeen. The aim of this longitudinal study was to compare the seasonal variation of serum 25-hydroxyvitamin D [25(OH)D] in postmenopausal women residing in Aberdeen (57 degrees N) and Surrey (51 degrees N). Women attended 3-monthly visits over 12 months, starting summer 2006. In Aberdeen, 338 Caucasian women (mean age+/-SD, 61.7+/-1.5 years); and at Surrey, 138 Caucasian women (61.4+/-4.5 years) and 35 Asian women (59.9+/-6.4 years) had serum 25(OH)D measured by IDS enzyme immunoassay. In winter/spring none of the Caucasian women living in Surrey had 25(OH)D<20 nmol/L, but nearly a quarter of women in Aberdeen were vitamin D-deficient. This number decreased to 4.2% in summer/autumn. For the Asian women 17.1% were vitamin D-deficient in summer, increasing to 58.1% in winter. Using higher 25(OH)D deficiency cut-offs, the percentage of women affected was much higher. These longitudinal data show clear differences in vitamin D status between the north and south of the UK, and marked ethnic differences. They are consistent with our previous data and with cross-sectional data from the 1958 birth cohort. The low vitamin D status may have implications for bone health and other health outcomes, which is currently being investigated in this publication group. The extent of vitamin D deficiency in Asian women residing in the South of England is of concern.

Academic health centres: managing the transition from good to great

Academic health centres (AHCs) bring significant economic and health benefits to a community. This study focuses on four integrated AHCs in the USA. They are described as the 'traditional great' or 'transformational great', where a number of common characteristics have been identified on how these organisations have demonstrated superior performance over time. The conceptual framework of 'good to great' provides a structure to explore key factors that support enhanced performance.

Selective fluconazole prophylaxis in high-risk babies to reduce invasive fungal infection

OBJECTIVES

To evaluate the impact of selective fluconazole prophylaxis on incidence of invasive fungal infection and emergence of fluconazole resistance in neonatal intensive care.

DESIGN

Retrospective study of very low birthweight (VLBW) babies (<1500 g birth weight) admitted to a neonatal intensive care unit (NICU) in the period 1 year before and after the implementation of an antifungal prophylaxis guideline.

PATIENTS

VLBW babies with an additional risk factor: colonisation of Candida species from surface sites with a central venous catheter; third generation cephalosporin treatment; or total duration of antibiotic treatment >10 days. Fluconazole protocol: Fluconazole 6 mg/kg for 3 weeks. Dose interval is every 72 h during the first 2 weeks of life. Thereafter, dose interval is reduced to every 48 h until 3 weeks old when daily fluconazole is given. Fluconazole is administered orally when enteral feeding achieved.

RESULTS

121 and 107 VLBW babies were admitted to the NICU in the year before and after the guideline was implemented, respectively. Data were available in 110 and 102 charts. 33/110 and 31/102 babies were eligible for fluconazole prophylaxis in the period before and after guideline implementation. 6/33 babies eligible for prophylaxis developed culture proven Candida sepsis before compared with no (0/31) babies after the guideline was implemented (p = 0.03). One baby (1/31) did develop probable Candida sepsis in the post guideline implementation period. During both study periods all Candida isolates remained fully susceptible to fluconazole.

CONCLUSIONS

Selective antifungal prophylaxis has reduced invasive fungal sepsis in one NICU without evidence of fluconazole resistance emerging.

Takotsubo cardiomyopathy: an uncommon cause of ST segment elevation in intensive care

A 63-year-old female developed respiratory failure and was admitted to the Intensive Care Unit for non-invasive ventilation, inotropic support and antibiotic therapy. The patient was initially stable but then suddenly deteriorated with acute pulmonary oedema requiring mechanical ventilation. An electrocardiogram showed an acute ST elevation myocardial infarction and the patient subsequently had an urgent coronary angiogram which revealed normal coronary arteries but apical ballooning characteristic of Takotsubo cardiomyopathy. A short review is provided of this relatively newly described heart syndrome which has the potential to present in numbers of intensive care patients. This case emphasises the importance of being aware of uncommon causes of acute ECG changes in the critically ill.

Non-local polymerization driven diffusion based model: general dependence of the polymerization rate to the exposure intensity

The nonlocal diffusion model proposed by Sheridan and coworkers has provided a useful interpretation of the nature of grating formation inside photopolymer materials. This model accounts for some important experimental facts, such as the cut-off of diffraction efficiency for high spatial frequencies. In this article we examine the predictions of the model in the case of a general dependence of the polymerisation rate with respect to the intensity pattern. The effects of this dependence on the different harmonic components of the polymerisation concentration will be investigated. The influence of the visibility on the different harmonic components will also be studied. These effects are compared to the effects of varying RD and sigmaD.

Higher androgens and weight gain with valproate compared with lamotrigine for epilepsy

BACKGROUND

Valproate is used widely for the treatment of epilepsy but has been associated with hyperandrogenism, hyperinsulinemia, and dyslipidemia. The mechanism for these associations is unknown, but they have been hypothesized to be secondary to valproate-associated weight gain. This study was conducted to test the hypothesis that the antiepileptic drug lamotrigine, which also has a broad spectrum of anti-seizure efficacy, would not be associated with endocrine abnormalities and would not cause weight gain.

OBJECTIVE AND METHODS

This open-label, cross-sectional study compared (1) endocrine and lipid measures during the early follicular phase of the menstrual cycle; (2) prevalence of menstrual disorders (from patient diaries recorded over three cycles); and (3) body weight of women with epilepsy on lamotrigine monotherapy (n=119) with those on valproate monotherapy (n=103) for <5 years.

RESULTS

Mean total serum testosterone and androstenedione levels were higher (P<0.02) in the valproate group compared with the lamotrigine group. More lamotrigine patients (87%) than valproate patients (77%) reported regular menstrual cycles at the Screening Visit. The prevalence of anovulation did not differ between lamotrigine and valproate. Mean HDL cholesterol levels were higher (P<0.01) with lamotrigine compared with valproate as were LDL and total cholesterol levels (P<0.05). Mean total insulin levels did not significantly differ between the groups. Whereas mean body weight in lamotrigine patients did not differ between the time lamotrigine treatment was initiated and the Study Visit, mean weight in valproate patients increased by 3.7 kg.

CONCLUSIONS

Compared with lamotrigine monotherapy, valproate monotherapy was associated with weight gain and higher androgen levels in women with epilepsy. These data suggest that the hyperandrogenism observed in some women using valproate for epilepsy may be secondary to drug therapy. Lamotrigine monotherapy may be more appropriate than valproate for women in whom reproductive endocrine or metabolic abnormalities are potential concerns, i.e. women with concerns about weight gain, diabetes, hirsutism, polycystic ovary syndrome, menstrual dysfunction or infertility.

The tolerability of lamotrigine in elderly patients with epilepsy

OBJECTIVE

To determine the tolerability of lamotrigine in elderly patients with epilepsy.

DESIGN

Pooled data from 13 lamotrigine clinical trials.

SETTING

Multicentre clinical trials conducted in primary care and neurology practices.

PARTICIPANTS

208 elderly patients (aged > or = 65 years) were identified: 146 lamotrigine-treated patients, 53 carbamazepine-treated patients and 9 phenytoin-treated patients.

INTERVENTIONS

Extent of exposure, incidence of drug-related adverse events, serious adverse events and study withdrawals were examined.

RESULTS

The median duration of exposure for lamotrigine monotherapy and add-on therapy was 24.1 and 47.4 weeks, respectively. The median daily dosage of lamotrigine was 100 mg for monotherapy (range 75 to 500 mg) and 300 mg for add-on therapy (range 25 to 700 mg). Overall, the incidence of drug-related adverse events was lower for lamotrigine than comparator drugs: 49% (72/146) for lamotrigine compared with 72% (38/53) for carbamazepine (p = 0.006), and 89% (8/9) for phenytoin (p = 0.035) although patient numbers in each treatment group were not comparable. Patients receiving lamotrigine reported incidences of somnolence (p = 0.012), rash (p = 0.034), and headache (nonsignificant) that were one-half the incidence reported with carbamazepine monotherapy. Rash was the most common reason for study withdrawal: 4% (6/146) lamotrigine, 17% (9/53) carbamazepine and 0% phenytoin. Seven (5%, 7/146) lamotrigine-treated patients, 4 (8%, 4/53) carbamazepine-treated patients and 1 (11%, 1/9) phenytoin-treated patient experienced drug-related serious adverse events.

CONCLUSION

Lamotrigine, used in the currently prescribed adult dosage regimen, was well tolerated in elderly patients with epilepsy.

A comparison of monotherapy with lamotrigine or carbamazepine in patients with newly diagnosed partial epilepsy

Monotherapy with lamotrigine or carbamazepine was evaluated in a multicentre open trial of patients aged 2 years and above with newly diagnosed partial epilepsy. A total of 417 patients were randomised to treatment with lamotrigine, while 201 patients received carbamazepine. Following a dose escalation period of 6 weeks, maintenance therapy (Weeks 7-24) was adjusted according to response. Efficacy was similar with both treatments (65% with lamotrigine, 73% with carbamazepine, P=0.085). Efficacy was assessed by the proportion of patients seizure free during the last 16 weeks of treatment; all subjects who remained in the study for at least 18 weeks after the week 4 visit were included in the analysis. More patients receiving lamotrigine completed the study (81%), compared with those receiving carbamazepine (77%). This difference was primarily due to discontinuation as a result of adverse events, reported by 34 (8%) of those treated with lamotrigine but 26 (13%) of those treated with carbamazepine. The proportion of patients who experienced adverse events in the lamotrigine group was lower (218 patients, 52%) compared with the carbamazepine group (120 patients, 60%). The proportion of patients with adverse events considered to be drug related was lower in the lamotrigine group (132 patients, 32%) compared with the carbamazepine group (83 patients, 41%). Somnolence was the only adverse event reported at an incidence of greater than 5% and where there was a difference of 5% or more between treatment groups (4% lamotrigine, 11% carbamazepine patients). The small subsets of elderly patients (aged 65 years or over) and paediatric patients (aged 2-12 years) also showed better tolerability to lamotrigine than to carbamazepine. In conclusion, monotherapy with lamotrigine is as effective as carbamazepine in patients with newly diagnosed partial epilepsy. Patients were able to tolerate lamotrigine better than carbamazepine, so more patients receiving lamotrigine were able to remain on therapy.